HAL Exports Added For Version 3.50

The table below lists the 17 exports that had been added to the HAL by version 3.50 from Windows NT 3.5 Service Pack 3. For the purpose of this study, with no other build of version 3.50 available for inspection, these exports are taken to have been added for version 3.50. Be aware that they might not date from the original release of version 3.50 or that they might have originated for a service-pack release of version 3.10.

For the table below, documentation status is summarised by colour coding so that more detail can be given as Remarks with less text. (If you read this website with scripts enabled, then hovering the mouse over any coloured text will produce a tooltip that shows why the text is coloured.) Functions that have their own non-trivial documentation are shown with no background colour. If the function is documented as reserved or obsolete, it is shaded red or shaded grey, respectively. Functions that appear to be completely undocumented are highlighted yellow. If a function is documented now but was not documented in the first contemporaneous Device Driver Kit (DDK), Windows Driver Kit (WDK) or Installable File System (IFS) Kit, then it is shaded yellow to retain some of its previous status. Many undocumented functions do at least have C-language declarations in one or another header file from the WDK. These are shaded orange, except for one special case. Some declarations are known only from “minwin” headers that Microsoft published in early editions of the WDK for Windows 10 which seem since to have been withdrawn. These are highlighted orange to indicate that public knowledge even of the declaration is exceptional.

Function Export History Documentation History Declaration History
ExAcquireFastMutex x86 only;
since 5.2 SP1, forwarded to ExiAcquireFastMutex in kernel;
since 6.2, forwarded to kernel
since 6.1 revision, documented start is 5.0 since 6.0, declared start is 5.0
ExReleaseFastMutex x86 only;
since 5.2 SP1, forwarded to ExiReleaseFastMutex in kernel;
since 6.2, forwarded to kernel
since 6.1 revision, documented start is 5.0 since 6.0, declared start is 5.0
ExTryToAcquireFastMutex x86 only;
since 5.2 SP1, forwarded to ExiTryToAcquireFastMutex in kernel;
since 6.2, forwarded to kernel
since 6.1 revision, documented start is 5.0 since 6.0, declared start is 5.0

The three functions for fast mutexes provide the first cases, chronologically, of HAL exports being reduced to forwards. The functions were for all practical effect moved to the kernel concurrently with the introduction of the x64 architecture, though the mechanism took a while to settle. For x64, these functions have only ever been exported from the kernel, not the HAL, not even as forwards.

Function Export History Documentation History Declaration History
HalAdjustResourceList x64 since 2004, forwarded to kernel    
HalAllProcessorsStarted x64 since 2004, forwarded to kernel    
HalAllocateCrashDumpRegisters x64 since 2004, forwarded to kernel before 6.0, declared since 6.0, declared start is 5.0
HalAssignSlotResources x64 since 2004, forwarded to kernel before 5.0, documented since 5.1, deprecated
since 6.0, declared start is 5.0
HalClearSoftwareInterrupt x64 since 2004, forwarded to kernel    
HalGetBusDataByOffset x64 since 2004, forwarded to kernel before 5.0, documented since 5.1, deprecated
since 6.0, declared start is 5.0
HalProcessorIdle x64 since 2004, forwarded to kernel    
HalSetBusData x64 since 2004, forwarded to kernel before 5.0, documented since 5.1, deprecated
since 6.0, declared start is 5.0
HalSetBusDataByOffset x64 since 2004, forwarded to kernel before 5.0, documented since 5.1, deprecated
since 6.0, declared start is 5.0
HalSetTimeIncrement discontinued in 6.3    

The particularities of how the few Hal functions that have ever been documented became obsolete are a separate story. Here it must suffice to note that starting with the DDK for Windows 2000, some of these functions are not declared at all if a macro NO_LEGACY_DRIVERS is defined.

Function Export History Declaration History
KfAcquireSpinLock x86 only;
since 6.2, forwarded to kernel
since 6.0, declared start is 5.0
KfLowerIrql x86 only
since 6.0, declared start is 5.0
KfRaiseIrql x86 only
since 6.0, declared start is 5.0
KfReleaseSpinLock x86 only;
since 6.2, forwarded to kernel
since 6.0, declared start is 5.0